The Canadian dollar surrendered early gains as it closed unchanged on Thursday after posting a nine-day high against its U.S. counterpart, ahead of Friday's release of the country's gross domestic product data for January.

U.S. crude prices settled 84 cents US higher at US$50.35 a barrel after Kuwait backed an extension of Organization of the Petroleum Exporting Countries production cuts to reduce a global glut.

"The big story is oil back above 50 ... it is a huge relief for CAD," said Greg Anderson, global head of foreign exchange strategy in New York.

Oil is one of Canada's major exports.        

The U.S. dollar rose after U.S. fourth-quarter gross domestic product growth figures were revised higher and softer-than-expected readings for German inflation weighed on the euro.                         

Some investors took the opportunity to sell euros against the Canadian dollar, Anderson said. "When euro started to sell off hard today, it just added wind to CAD sails."

The Canadian dollar ended at $1.3334 to the greenback, or 75.00 cents US, little changed from Wednesday's close of $1.3333, or 75.00 cents US. The currency's weakest level of the session was $1.3347, while it touched its strongest since March 21 at $1.3278.

The Wall Street Journal reported that President Donald Trump's administration was signaling to Congress that it would seek mostly modest changes to the North American Free Trade Agreement in upcoming negotiations with Mexico and Canada. Canada exports about 75 per cent of its exports to the United States, and traders are closely following developments in U.S. trade policy. 

In domestic data, producer prices edged up 0.1 per cent in February from January, which was less than the 0.3 per cent increase analysts had expected. Still, the year-on-year gain picked up to 3.5 per cent from 2.5 per cent.

On Friday, Canada issues January GDP data, expected by economists to rise 0.3 per cent. That could set the stage for a stronger performance in the first quarter than initially expected.         

Canadian government bond prices were lower across the yield curve, with the two-year  down 4.5 cents to yield 0.748 per cent, its highest since March 24, and the 10-year falling 33 cents to yield 1.632 per cent.